Type of primitive functions in lazy evaluation

I want to know what the exact type of primitive functions in lazy functional programming languages like Haskell is. Let's say thunks are evaluated to objects of weak head normal form. Then, what should be the type of primitive functions in strict languages like C? My guesses are: primitive1 : (thunk, thunk, ...) -> thunk primitive2 : (thunk, thunk, ...) -> object I think primitiv

惰性评估中原始函数的类型

我想知道像Haskell这样的懒惰函数式编程语言中原始函数的确切类型是什么。 假设thunk被评估为弱头标准形式的对象。 那么,像C这样的严格语言中的原始函数应该是什么类型呢? 我的猜测是: primitive1 : (thunk, thunk, ...) -> thunk primitive2 : (thunk, thunk, ...) -> object 我认为原始函数应该通过thunk作为参数,因为它们可能不需要其中的一些。 但是,我不知道他们是否应该返回一个thunk或者被评估对象,

Introduction to GUI programming with c

I'm new GUI and programming as whole and so far I have a general understanding of c and have spent quite some time writing console applications. I'm trying to learn GUI but have so far been unsuccessful. I've tried learning wxwidgets (through official documentation), gtk (through official documentation) and win32 (forgers win32 tutorial) but still haven't quite gotten there.

用c编程介绍GUI编程

我是新的GUI和编程整体,到目前为止我对c有一个大致的了解,并花了相当一段时间编写控制台应用程序。 我正在尝试学习GUI,但迄今为止一直不成功。 我试过学习wxwidgets(通过官方文档),gtk(通过官方文档)和win32(伪造win32教程),但仍然没有完全到达那里。 我仍然很想但似乎找不到任何好材料。 对于初学者,你会推荐什么? 如果你严格限于C,你只有几个选择。 GTK +对于初学者来说可能是最简单的。 像C ++这样

How can you read values from an open application in Windows?

I want to create a program or use a program that will read the memory values out of another application. Does anyone know of an application/library that will do this? The target app is this. I would like to read the exchange rate values from it. I'm an experienced c# programmer, but have never worked with the Win32/user32 api which is what I'm assuming I'll have to deal with to

你如何读取Windows中打开的应用程序的值?

我想创建一个程序或使用一个程序来读取另一个应用程序中的内存值。 有谁知道会做这个的应用程序/库吗? 目标应用是这个。 我想从中读取汇率值。 我是一名经验丰富的c#程序员,但从未与Win32 / user32 api合作过,我假设我必须处理这个问题才能解决这个问题。 任何帮助,让我朝着正确的方向是非常感谢。 更新:我设法使用Spy ++来获取窗口句柄,所以我确信我可以得到一些值。 通常,应用程序在对话框中以一致的庄园

how do you add a NEW LINE character in the string portion of an ActionLink?

I'm building a Ajax.ActionLink in C# which starts: <%= Ajax.ActionLink("f lastname", ...more stuff and I'd like there to be a new line character between the words "f" and "lastname". How can I accomplish this? I thought the special character was n but that doesn't work, and <br> doesn't work either. You might have to revert to doing something lik

如何在ActionLink的字符串部分添加NEW LINE字符?

我在C#中构建了一个Ajax.ActionLink,它开始: <%= Ajax.ActionLink("f lastname", ...more stuff 我希望在“f”和“lastname”之间有一个新的字符。 我怎样才能做到这一点? 我认为这个特殊字符是 n,但这不起作用,并且<br>也不起作用。 您可能不得不恢复如下操作: <a href="<%= Url.Action("action") %>">f<br />last</a> 然后手动连接Ajax位。 尝试这个: <%= Ajax.ActionLink("f

using if else with eval in aspx page

Is there a way to use an else if on the following eval on the aspx page . Currently my div is as follows : <div class="tooltip" style="display: none"> <div style="text-align: center; font-weight: normal"> Value = <%# Eval("Percentage") + "%" %> </div> </div>

如果在aspx页面中使用eval,则使用if

有没有一种方法可以在aspx页面上的以下评估中使用else。 目前我的div如下: <div class="tooltip" style="display: none"> <div style="text-align: center; font-weight: normal"> Value = <%# Eval("Percentage") + "%" %> </div> </div> 我想在我的div上使用以下逻辑: If(P

using c# condtional operator in vb.net

Possible Duplicate: Is there a conditional ternary operator in VB.NET? I have the folowing code in asp.net for c# website but i have to use this code in vb.net site but im unable to convert the code even code translator please help me to do this.here is my code <asp:CheckBox ID="chkStatus" runat="server" AutoPostBack="true" OnCheckedChanged="chkStatus_OnChecke

在vb.net中使用c#condtional运算符

可能重复: VB.NET中是否有条件的三元运算符? 我在asp.net for c#网站下面的代码,但我必须在vb.net网站使用此代码,但即时代码无法转换代码甚至代码翻译,请帮我做到这一点。我的代码 <asp:CheckBox ID="chkStatus" runat="server" AutoPostBack="true" OnCheckedChanged="chkStatus_OnCheckedChanged" Checked='<%# Convert.ToBoolean(Eval("Approved")

What is the VB.NET equivalent of the C# ? operator?

This question already has an answer here: Is there a conditional ternary operator in VB.NET? 8 answers Historically, IIf was commonly used for that - but that does not use short-circuiting so is not quite the same. However, there is now a 3-part If : hp.pt = If(iniFile.GetValue("System", "PT").ToUpper().Equals("H"), PT.PA, PT.SP) that does use short-circuiting, and thus is identical to th

什么是C#的VB.NET等价物? 运营商?

这个问题在这里已经有了答案: VB.NET中是否有条件的三元运算符? 8个答案 从历史上看, IIf通常用于此 - 但不使用短路,因此不完全相同。 但是,现在有一个3部分If : hp.pt = If(iniFile.GetValue("System", "PT").ToUpper().Equals("H"), PT.PA, PT.SP) 它使用短路,因此与C#中的条件运算符相同。 您可以使用If运算符hp.pt = If(iniFile.GetValue("System", "PT").ToUpper().Equals("H"), PT.PA, PT.SP) 尝试使用If

Make A Date Null

Can someone help me fix my code I am trying to put null in sql server through a function that is excepting _dtSWO. If I set _dtSWO = Nothing it returns #12:00:00 AM# which throws an exception. The field is nullable in sql server I just want it to return a blank Dim _swoDate As String = udSWOReceivedDateDateEdit.Text Dim _dtSWO As Date If _swoDate <> "" Then

使日期为空

有人可以帮助我修复我的代码,我试图通过一个函数,除了_dtSWO在SQL服务器中的空值。 如果我设置_dtSWO = Nothing,它会返回#12:00:00 AM#,这会引发异常。 该字段在SQL Server中可以为空,我只是希望它返回一个空格 Dim _swoDate As String = udSWOReceivedDateDateEdit.Text Dim _dtSWO As Date If _swoDate <> "" Then _dtSWO = Date.Parse(udSWOReceivedDateDateEdit.Text)

What's your favorite LINQ to Objects operator which is not built

With extension methods, we can write handy LINQ operators which solve generic problems. I want to hear which methods or overloads you are missing in the System.Linq namespace and how you implemented them. Clean and elegant implementations, maybe using existing methods, are preferred. 追加和前置/// <summary>Adds a single element to the end of an IEnumerable.</summary> /// <type

你最喜欢的LINQ to Objects运算符是不是构建的

通过扩展方法,我们可以编写方便的LINQ操作符来解决一般问题。 我想知道在System.Linq命名空间中缺少哪些方法或重载以及如何实现它们。 清洁和优雅的实现,可能使用现有的方法,是首选。 追加和前置/// <summary>Adds a single element to the end of an IEnumerable.</summary> /// <typeparam name="T">Type of enumerable to return.</typeparam> /// <returns>IEnumerable containing all

Returning the terminal cursor to start

I'm writing a filter (in a pipe destined for a terminal output) that sometimes needs to "overwrite" a line that has just occurred. It works by passing stdin to stdout character-by-character until a n is reached, and then invoking special behaviour. My problem regards how to return to the beginning of the line. The first thing I thought of was using a r or the ANSI sequence 33[1G

返回终端光标开始

我正在编写一个过滤器(在发往终端输出的管道中),有时需要“覆盖”刚发生的一行。 它的工作原理是将stdin传递给标准的字符,直到达到n ,然后调用特殊行为。 我的问题是如何回到行的开头。 我首先想到的是使用r或ANSI序列33[1G 。 但是,如果线条足够长以包裹在终端上(并因此导致其滚动),则这些将仅将光标移回当前物理线。 我的第二个想法是跟踪行的长度(从前n传递的字符n ),然后多次echo b 。 但是,如果该行包含